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Old 03-02-2014, 03:11   #1
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32v to 24v idea

Hello,

I have a new 32v banks for the Port and Starboard Detroit Diesels on the Bertram.

I only have the engines, engine room blowers, and all bilges on the 32v. I would like to still use the 32v banks for the fresh water and drinking water pumps.

If I connect 12 diodes in series (50 amp each). Each diode will always lower voltage by 0.7 volts when in any circuit. Installing 12 in series will lower 32v to 24v. Installing the set on a good heat sink should keep everything cool and functioning smooth.

Has anyone ever tried this ??

Alan
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Old 03-02-2014, 04:34   #2
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Re: 32v to 24v idea

Quote:
Originally Posted by Hkalan View Post
Hello,

I have a new 32v banks for the Port and Starboard Detroit Diesels on the Bertram.

I only have the engines, engine room blowers, and all bilges on the 32v. I would like to still use the 32v banks for the fresh water and drinking water pumps.

If I connect 12 diodes in series (50 amp each). Each diode will always lower voltage by 0.7 volts when in any circuit. Installing 12 in series will lower 32v to 24v. Installing the set on a good heat sink should keep everything cool and functioning smooth.

Has anyone ever tried this ??

Alan
Why wouldn't you just use a DC-DC converter? It's a lot more efficient to transform the power, than just knock out the voltage like that, turning it into heat.

Newmar make some which will work: DC-DC Converters - Standard SeriesDC-DC Converters - Standard SeriesDC-DC Converters - Standard Series
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Old 03-02-2014, 05:03   #3
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Re: 32v to 24v idea

I agree, a DC-DC converter is the way to go. My electric winches are probably the only thing aboard that keeps me from going to a higher voltage on my house bank!
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Old 03-02-2014, 08:52   #4
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Re: 32v to 24v idea

DC-DC converters, while very efficient, can be expensive when putting out up to 50 amps for motors. An alternative you might like to consider is putting in a 32 volt inverter and using 110 volt pumps, etc. We did this on our boat and were able to use domestic water pump systems at a lower cost and higher reliability than the DC marine equivalent. We added 120 volt hydraulic pump for auto pilot, 120 volt wash-down pump, domestic ice maker and refrigerator compressor.

You would get the added advantage of having AC voltage for appliances and also get an inverters with a built in charging system so you will charge your 32 volt battery when on shore power.
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Old 03-02-2014, 17:19   #5
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Re: 32v to 24v idea

Hello,

I agree about the DC to DC converter, but that will take over a month to get here... I have them for the port and starboard LED lighting, and the new 24v Tecma heads. Now that the Galley Maid 32v fresh water pump died, was looking for a 40 day temporary solution, and if anyone ever tried the "Diode" theory. 35 amp to 80 amp diodes are readily available around me.

I could also run off 3 of the 8v batteries for 24v, but discharging a brand new 32v bank unevenly, goes against everything that is best for the bank (no matter how short of a time it may be).

Outback still make a 32v inverter that I have onboard, but those may be drawing to the end of their popularity WINK

The solar panels keep the 32v bank at a very happy 34.5v float state. For now the 32v is doing a great job... If it ain't broke, don't fix it... SMILE

Thanks so much !!!

Alan
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Old 03-02-2014, 22:09   #6
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Re: 32v to 24v idea

why are you powered this stuff off your engine batteries?

if a bunch of stuff is 24v. install a 24v house bank. nothing should be off the engine batteries except the engines.
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Old 04-02-2014, 01:32   #7
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Re: 32v to 24v idea

Hello,

That is how Bertram made it !!!

I am saving for a LifePO4 24v 800Ah bank this summer...

Until then, this has worked since 1982.

Thanks

Alan
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Old 04-02-2014, 02:01   #8
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Re: 32v to 24v idea

I have never gotten over the biggest mistake that I probably made in my life.

In 2001, the boat I purchased was 32 volt boat...52 footer.


As a Marine Electrician, I saw the hand-writing on the wall...and changed it to 12 volt.

One of the biggest mistakes, Ive made in my lifetime was to convert to 12 volt.

Knowing, what I know today, I would be 32 volt. Waiting to go to 32 volt LiFePo4.

32volt LiFePo4, is the perfect solution for a marine house bank, inc. inverter, lights, and pumps.

LiFePo4 was innately designed for 32 volt nominal.

Lloyd



Quote:
Originally Posted by Hkalan View Post
Hello,

That is how Bertram made it !!!

I am saving for a LifePO4 24v 800Ah bank this summer...

Until then, this has worked since 1982.

Thanks

Alan
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